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        <h2><strong>IViewportTransform</strong>
          class
        </h2>
        
<button id="show-inherited" class="show-inherited">Hide inherited</button>
<div class="doc">
<p>This is the viewport transform used from drawing.
Use yFlip if you are drawing from the top-left corner.</p>
<pre class="source">
class IViewportTransform {
  IViewportTransform(Vector e, Vector c, num s) :
    extents = new Vector.copy(e),
    center = new Vector.copy(c),
    scale = s;

  /**
   * if we flip the y axis when transforming.
   */
  bool yFlip;

  /**
   * This is the half-width and half-height.
   * This should be the actual half-width and 
   * half-height, not anything transformed or scaled.
   */
  Vector extents;

  /**
   * Returns the scaling factor used in converting from world sizes to rendering
   * sizes.
   */
  num scale;
  
  /**
   * center of the viewport.
   */
  Vector center;

  /**
   * Sets the transform's center to the given x and y coordinates,
   * and using the given scale.
   */
  void setCamera(num x, num y, num s) {
    center.setCoords(x, y);
    scale = s;
  }
  /**
   * The current translation is the difference in canvas units between the
   * actual center of the canvas and the currently specified center. For
   * example, if the actual canvas center is (5, 5) but the current center is
   * (6, 6), the translation is (1, 1).
   */
  Vector get translation() {
    Vector result = new Vector.copy(extents);
    result.subLocal(center);
    return result;
  }

  void set translation(Vector translation) {
    center.setFrom(extents);
    center.subLocal(translation);
  }


  /**
   * Takes the world coordinate (argWorld) puts the corresponding
   * screen coordinate in argScreen.  It should be safe to give the
   * same object as both parameters.
   */
  void getWorldToScreen(Vector argWorld, Vector argScreen) {
    // Correct for canvas considering the upper-left corner, rather than the
    // center, to be the origin.
    num gridCorrectedX = (argWorld.x * scale) + extents.x;
    num gridCorrectedY = extents.y - (argWorld.y * scale);

    argScreen.setCoords(gridCorrectedX + translation.x, gridCorrectedY +
        -translation.y);
  }

  /**
   * Takes the screen coordinates (argScreen) and puts the
   * corresponding world coordinates in argWorld. It should be safe
   * to give the same object as both parameters.
   */
  void getScreenToWorld(Vector argScreen, Vector argWorld) {
    num translationCorrectedX = argScreen.x - translation.x;
    num translationCorrectedY = argScreen.y + translation.y;

    num gridCorrectedX = (translationCorrectedX - extents.x) / scale;
    num gridCorrectedY = ((translationCorrectedY - extents.y) * -1) / scale;
    argWorld.setCoords(gridCorrectedX, gridCorrectedY);
  }
}
</pre>
</div>
<h3>Subclasses</h3>
<p>
<span class="type-box"><span class="icon-class"></span><a href="../box2d_html/CanvasViewportTransform.html">CanvasViewportTransform</a></span></p>
<div>
<h3>Constructors</h3>
<div class="method"><h4 id="IViewportTransform">
<button class="show-code">Code</button>
new <strong>IViewportTransform</strong>(<a href="../box2d_html/Vector.html">Vector</a> e, <a href="../box2d_html/Vector.html">Vector</a> c, num s) <a class="anchor-link" href="#IViewportTransform"
              title="Permalink to IViewportTransform.IViewportTransform">#</a></h4>
<div class="doc">
<pre class="source">
IViewportTransform(Vector e, Vector c, num s) :
  extents = new Vector.copy(e),
  center = new Vector.copy(c),
  scale = s;
</pre>
</div>
</div>
</div>
<div>
<h3>Properties</h3>
<div class="field"><h4 id="center">
<button class="show-code">Code</button>
<a href="../box2d_html/Vector.html">Vector</a>         <strong>center</strong> <a class="anchor-link"
            href="#center"
            title="Permalink to IViewportTransform.center">#</a>
        </h4>
        <div class="doc">
<p>center of the viewport.</p>
<pre class="source">
Vector center;
</pre>
</div>
</div>
<div class="field"><h4 id="extents">
<button class="show-code">Code</button>
<a href="../box2d_html/Vector.html">Vector</a>         <strong>extents</strong> <a class="anchor-link"
            href="#extents"
            title="Permalink to IViewportTransform.extents">#</a>
        </h4>
        <div class="doc">
<p>This is the half-width and half-height.
This should be the actual half-width and
half-height, not anything transformed or scaled.</p>
<pre class="source">
Vector extents;
</pre>
</div>
</div>
<div class="field inherited"><h4 id="runtimeType">
<button class="show-code">Code</button>
final Type         <strong>runtimeType</strong> <a class="anchor-link"
            href="#runtimeType"
            title="Permalink to IViewportTransform.runtimeType">#</a>
        </h4>
        <div class="inherited-from">inherited from Object </div><div class="doc">
<p>A representation of the runtime type of the object.</p>
<pre class="source">
external Type get runtimeType;
</pre>
</div>
</div>
<div class="field"><h4 id="scale">
<button class="show-code">Code</button>
num         <strong>scale</strong> <a class="anchor-link"
            href="#scale"
            title="Permalink to IViewportTransform.scale">#</a>
        </h4>
        <div class="doc">
<p>Returns the scaling factor used in converting from world sizes to rendering
sizes.</p>
<pre class="source">
num scale;
</pre>
</div>
</div>
<div class="field"><h4 id="translation">
<button class="show-code">Code</button>
<a href="../box2d_html/Vector.html">Vector</a>         <strong>translation</strong> <a class="anchor-link"
            href="#translation"
            title="Permalink to IViewportTransform.translation">#</a>
        </h4>
        <div class="doc">
<p>The current translation is the difference in canvas units between the
actual center of the canvas and the currently specified center. For
example, if the actual canvas center is (5, 5) but the current center is
(6, 6), the translation is (1, 1).</p>
<pre class="source">
Vector get translation() {
  Vector result = new Vector.copy(extents);
  result.subLocal(center);
  return result;
}
</pre>
<pre class="source">
void set translation(Vector translation) {
  center.setFrom(extents);
  center.subLocal(translation);
}
</pre>
</div>
</div>
<div class="field"><h4 id="yFlip">
<button class="show-code">Code</button>
bool         <strong>yFlip</strong> <a class="anchor-link"
            href="#yFlip"
            title="Permalink to IViewportTransform.yFlip">#</a>
        </h4>
        <div class="doc">
<p>if we flip the y axis when transforming.</p>
<pre class="source">
bool yFlip;
</pre>
</div>
</div>
</div>
<div>
<h3>Operators</h3>
<div class="method inherited"><h4 id="==">
<button class="show-code">Code</button>
bool <strong>operator ==</strong>(other) <a class="anchor-link" href="#=="
              title="Permalink to IViewportTransform.operator ==">#</a></h4>
<div class="inherited-from">inherited from Object </div><div class="doc">
<p>The equality operator.</p>
<p>The default behavior for all <code>Object</code>s is to return true if and
only if <code>this</code> and 
<span class="param">other</span> are the same object.</p>
<p>If a subclass overrides the equality operator it should override
the <code>hashCode</code> method as well to maintain consistency.</p>
<pre class="source">
bool operator ==(other) =&gt; identical(this, other);
</pre>
</div>
</div>
</div>
<div>
<h3>Methods</h3>
<div class="method"><h4 id="getScreenToWorld">
<button class="show-code">Code</button>
void <strong>getScreenToWorld</strong>(<a href="../box2d_html/Vector.html">Vector</a> argScreen, <a href="../box2d_html/Vector.html">Vector</a> argWorld) <a class="anchor-link" href="#getScreenToWorld"
              title="Permalink to IViewportTransform.getScreenToWorld">#</a></h4>
<div class="doc">
<p>Takes the screen coordinates (argScreen) and puts the
corresponding world coordinates in argWorld. It should be safe
to give the same object as both parameters.</p>
<pre class="source">
void getScreenToWorld(Vector argScreen, Vector argWorld) {
  num translationCorrectedX = argScreen.x - translation.x;
  num translationCorrectedY = argScreen.y + translation.y;

  num gridCorrectedX = (translationCorrectedX - extents.x) / scale;
  num gridCorrectedY = ((translationCorrectedY - extents.y) * -1) / scale;
  argWorld.setCoords(gridCorrectedX, gridCorrectedY);
}
</pre>
</div>
</div>
<div class="method"><h4 id="getWorldToScreen">
<button class="show-code">Code</button>
void <strong>getWorldToScreen</strong>(<a href="../box2d_html/Vector.html">Vector</a> argWorld, <a href="../box2d_html/Vector.html">Vector</a> argScreen) <a class="anchor-link" href="#getWorldToScreen"
              title="Permalink to IViewportTransform.getWorldToScreen">#</a></h4>
<div class="doc">
<p>Takes the world coordinate (argWorld) puts the corresponding
screen coordinate in argScreen.  It should be safe to give the
same object as both parameters.</p>
<pre class="source">
void getWorldToScreen(Vector argWorld, Vector argScreen) {
  // Correct for canvas considering the upper-left corner, rather than the
  // center, to be the origin.
  num gridCorrectedX = (argWorld.x * scale) + extents.x;
  num gridCorrectedY = extents.y - (argWorld.y * scale);

  argScreen.setCoords(gridCorrectedX + translation.x, gridCorrectedY +
      -translation.y);
}
</pre>
</div>
</div>
<div class="method inherited"><h4 id="hashCode">
<button class="show-code">Code</button>
int <strong>hashCode</strong>() <a class="anchor-link" href="#hashCode"
              title="Permalink to IViewportTransform.hashCode">#</a></h4>
<div class="inherited-from">inherited from Object </div><div class="doc">
<p>Get a hash code for this object.</p>
<p>All objects have hash codes. Hash codes are guaranteed to be the
same for objects that are equal when compared using the equality
operator <code>==</code>. Other than that there are no guarantees about
the hash codes. They will not be consistent between runs and
there are no distribution guarantees.</p>
<p>If a subclass overrides <code>hashCode</code> it should override the
equality operator as well to maintain consistency.</p>
<pre class="source">
external int hashCode();
</pre>
</div>
</div>
<div class="method"><h4 id="IViewportTransform">
<button class="show-code">Code</button>
new <strong>IViewportTransform</strong>(<a href="../box2d_html/Vector.html">Vector</a> e, <a href="../box2d_html/Vector.html">Vector</a> c, num s) <a class="anchor-link" href="#IViewportTransform"
              title="Permalink to IViewportTransform.IViewportTransform">#</a></h4>
<div class="doc">
<pre class="source">
IViewportTransform(Vector e, Vector c, num s) :
  extents = new Vector.copy(e),
  center = new Vector.copy(c),
  scale = s;
</pre>
</div>
</div>
<div class="method inherited"><h4 id="noSuchMethod">
<button class="show-code">Code</button>
<strong>noSuchMethod</strong>(String name, List args) <a class="anchor-link" href="#noSuchMethod"
              title="Permalink to IViewportTransform.noSuchMethod">#</a></h4>
<div class="inherited-from">inherited from Object </div><div class="doc">
<p><code>noSuchMethod</code> is invoked when users invoke a non-existant method
on an object. The name of the method and the arguments of the
invocation are passed to <code>noSuchMethod</code>. If <code>noSuchMethod</code>
returns a value, that value becomes the result of the original
invocation.</p>
<p>The default behavior of <code>noSuchMethod</code> is to throw a
<code>noSuchMethodError</code>.</p>
<pre class="source">
external Dynamic noSuchMethod(String name, List args);
</pre>
</div>
</div>
<div class="method inherited"><h4 id="Object">
<button class="show-code">Code</button>
const <strong>Object</strong>() <a class="anchor-link" href="#Object"
              title="Permalink to IViewportTransform.Object">#</a></h4>
<div class="inherited-from">inherited from Object </div><div class="doc">
<p>Creates a new <code>Object</code> instance.</p>
<p><code>Object</code> instances have no meaningful state, and are only useful
through their identity. An <code>Object</code> instance is equal to itself
only.</p>
<pre class="source">
const Object();
</pre>
</div>
</div>
<div class="method"><h4 id="setCamera">
<button class="show-code">Code</button>
void <strong>setCamera</strong>(num x, num y, num s) <a class="anchor-link" href="#setCamera"
              title="Permalink to IViewportTransform.setCamera">#</a></h4>
<div class="doc">
<p>Sets the transform's center to the given x and y coordinates,
and using the given scale.</p>
<pre class="source">
void setCamera(num x, num y, num s) {
  center.setCoords(x, y);
  scale = s;
}
</pre>
</div>
</div>
<div class="method inherited"><h4 id="toString">
<button class="show-code">Code</button>
String <strong>toString</strong>() <a class="anchor-link" href="#toString"
              title="Permalink to IViewportTransform.toString">#</a></h4>
<div class="inherited-from">inherited from Object </div><div class="doc">
<p>Returns a string representation of this object.</p>
<pre class="source">
external String toString();
</pre>
</div>
</div>
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